How to log into System on Android: hidden menus, ADB and Engineering Mode

Access to system partitions Android opens up opportunities for fine-tuning your smartphone that are not available in the standard interface. Here you can change network parameters, calibrate sensors, enable debugging functions, or even unlock hidden manufacturer options. However, not everyone knows that the path to these settings lies through special engineering menus, commands ADB or hardware key combinations.

It is important to understand: system partitions (/system, /vendor) are protected from accidental changes. Manufacturers restrict access to them to prevent damage to the firmware or disruption of the device. But if you need check hardware parameters, calibrate the screen or enable hidden functions (for example, battery diagnostics), there are legal ways to do this without obtaining root access. This article contains current methods for Android 10–14, including devices Samsung, Xiaomi, Realme and other brands.

1. What is "System" on Android and why go there?

Partition /system in Android is a protected memory area where the following are stored:

• 📱 System applications (for example, Settings.apk, Phone.apk)
• ⚙️ Configuration files (network, sound, display settings)
• 🔧 Libraries and drivers for hardware components
• 🛡️ Policies security (permissions, certificates)

By default, the user cannot change files in this section - they are read-only (read-onlyHowever, through the engineering menus or ADB you can:

• 🔍 View hidden parameters (for example, the antenna signal level in decibels)
• 📊 Test hardware components (camera, speakers, accelerometer)
• 🔄 Reset sensor calibration (gyroscope, compass)
• 🚀 Enable experimental functions (for example Force 4G Only on some firmware)

⚠️ Attention: Changing system files without understanding the consequences can lead to loss of warranty, cyclic reboot (bootloop) or locking the bootloader. On devices with Samsung Knox or Google Titan M such actions may trigger hardware security flags, which will make it impossible to use services like Samsung Pay or Google Wallet.

If your goal is just to view technical information (for example, IMEI, version of the radio module. data-i="90">battery status or battery status, it is enough to use engineering menu (Engineering Mode). For deep changes (modification of files in /system) you will need ADB or root.

2. Method 1: Engineering menu (Engineering Mode) - without a PC and root

The easiest way to access system parameters is to use hidden engineering menu. It is available on all Android devices, but the path to it depends on the manufacturer and firmware version.

For most smartphones (Xiaomi, Redmi, POCO, Realme, Oppo, Vivo), a universal code is suitable:

##4636##

After entering, a menu will open "Testing" (Testing) with tabs:

• 📶 Phone information (Phone Information) - network data, IMEI, signal
• 🔋 Battery information (Battery Information) - charge level, temperature, voltage
• 📊 Usage statistics (Usage Statistics) - application operating time
• 🔧 Wi-Fi settings (Wi-Fi Information) - signal strength, MAC address

On devices Samsung the engineering menu opens another code:

#0#

Here you can test display (colors, touchscreen), speakers, vibration and camera.

⚠️ Attention: On some firmware (for example, MIUI 14+ or One UI 6+) the engineering menu may be blocked. If nothing happens after entering the code, try using ADB (method 3) or check if access is disabled through security policies (for example, on corporate devices).

Check the real network signal level (in dBm)

Find out exact battery voltage and temperature

Test the operation of all sensors (gyroscope, illumination)

Enable debug logs to diagnose problems

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3. Method 2: Codes for accessing hidden menus (by brand)

Each manufacturer adds unique ones to the firmware Service codes, which provide access to different sections of the system. Below are the current combinations for popular brands (2026–2026).

On some devices (for example, Samsung Galaxy S23+ or Xiaomi 14 Pro) codes may not work due to security policies. In this case:

1. Try entering codes through Phone application, and not through the lock screen.
2. If the code does not work, check if security updateis installed that blocks engineering menus (relevant for Android 13+).
3. Use ADB (method 3) as an alternative.

4. Method 3: Access via ADB (for advanced users)

ADB (Android Debug Bridge) is a tool from Googlethat allows you to control the device via the PC command line. With it you can:

• 📁 View. files in /system (without write permissions)
• 🔧 Execute debugging commands (for example, dumpsys for diagnostics)
• 🔄 Reboot into recovery modes or fastboot

To get started:

1. Enable Debugging via USB in the developer settings (Settings → About phone → Build number (press 7 times) → For developers → USB debugging).
2. Download ADB Tools (official package from Google).
3. Connect your phone to the PC and check the connection with the command:

   adb devices

Examples of useful commands for accessing system information:

adb shell dumpsys battery # Battery information
adb shell dumpsys wifi # Wi-Fi information
adb shell getprop ro.build.version.sdk # Android SDK version
adb shell ls /system/app # List of system applications

⚠️ Attention: Commands adb pull /system or adb push to write to /system will not work without root access. Trying to change files in this section will result in an error Read-only file system. Full access requires unlocking the bootloader and installation Magisk.

1. Reinstall drivers Google USB Driver.

2. Use another USB cable (preferably the original one).

3. Enable the mode Transfer files (MTP) when connecting.

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5. Method 4: Using applications to view system information

If you do not need deep changes, but only view system data, you can do without ADB codes. There are applications that collect information from protected sections and display it in a convenient form. The best of them:

• 📊 CPU-Z - shows detailed information about the processor, memory, sensors and battery. Free, without unnecessary water.
• 🔍 DevCheck - analyzes hardware, including data about SoC, GPU and RAM.
• 🛠️ AIDA64 - professional diagnostic tool, supports performance tests.
• 🔋 AccuBattery - monitors battery condition, shows actual capacity and wear.

• Google Pixel: officially supports unlocking via fastboot oem unlock.
• Xiaomi: requires waiting 7–30 days after linking the account Mi.
• Samsung: unlocking the bootloader resets Knox, which voids the warranty.
• OnePlus/Realme: the process is similar Pixel, but a special utility from the manufacturer may be required.

adb shell mount | grep system